• Optimization of Growth Conditions in Minimal Media for Production of Nucleolin Protein

      Yang, Danzhou; Bruce Carver, Megan; Brewer, William Ryan; Yang, Danzhou; Bruce Carver, Megan; College of Pharmacy, The University of Arizona (The University of Arizona., 2016)
      Objectives: The purpose of this experiment is to compare NUC1234 expression levels from E. coli cultures by manipulating cell cultures according to the optical density (OD595) at which protein expression is induced, and the harvest time after induction. Methods: E. coli BL21(DE3) cells transformed with DNA to produce NUC1234 were plated and then grown in minimal media for protein expression. They were induced at a variety of optical densities and harvested at different times post-induction. Protein quantities from each sample were then compared using a protein determination assay and an SDS-PAGE gel. Results: The sample induced at an OD595 of 0.5 yielded a lower concentration of protein (0.874409mg/ml) compared to other samples; however, it visualized as a stronger band in the SDS-PAGE gel. The sample harvested at 6 hours yielded the largest protein concentration (1.347215mg/ml) among all active samples and appeared as bold as, or bolder than, those harvested at other times. Conclusions: The results of the protein assay study and gel visualization suggest that the optimal conditions for the production of NUC1234 are growth to an OD595 of 0.5 before induction of protein expression and a harvest time of 6 hours after induction.